Lifting mechanism attachment for lift trucks



March 19, 1957 .1.5. PAPPATHATos x-:TAL 2,785,817

LIFTING MECHANISM ATTACHMENT FOR LIFT TRUCKS 3 Sheets-Sheet l Filed NOV 20, 1953 wlfnuva ik mms/T0115 JAN/2s 5 PAPPA Tf-/Aros ,EL/wf@ /z G/ 71s ATTORNEYS March 19, 1957 J. s. PAPPATHA-I'os ETAI. 2,785,817

LIF'TING MECHANISM ATTACHMENT FOR LIFT TRUCKS Filed Nov 20, 1953 3 Sheets-Sheet 2 JAMES 5. PAPPA THATOS M5L? f." G/ T5 A Tron/vans March 19, 1957 Filed Nov 20, 1953 J. s. PAPPATHATos ErAL A 2,785,817

LIFTING MECHANISM ATTACHMENT FOR LIFT TRUCKS 3 Shets-Sheet 3 A 7- ToP/v: Ys

United States Patent i 2,785,817 LIFTING MECHANSh/ TTACHMENT FR LIFT TRUCKS .lames S. Pappathatos, Minneapolis, and Elmer- F. Gils,

St. Paul, Minn., assignors to Unit Mannfacturmg Company, Minneapolis, Minn., a corporation ot' Minnesota Application November 26, 1953, Serial No. 393,267

6 Claims. (Cl. 21a- 513) This invention relates in general to new and useful improvements in lifting mechanisms and more particularly to new and useful improvements in a lifting mechanism of the type utilized in factories, shops, garages, etc., for elevating various objects.

It is an object of this invention to provide a new and useful lifting mechanism which is portable, simple 1n construction and capable of quick and easy operation.

It is a further object of this invention to provide a new and useful lifting mechanism having a construction of maximum efficiency and versatility, whereby the mechanism may be adapted to a variety of uses and whereby a variety of objects may be lifted.

Another object of this invention is to provide a new and useful lifting mechanism having a vertically reciprocal trolley adapte-:1 for cooperation with versatile lifting structure.

Another object of this invention is to provide a new and useful lifting mechanism having versatile means for engaging the load being lifted.

lt is also an object of this invention to provide a hydraulic lift having means for elevating a variety of ob- 'ects. J Further objects of this invention reside in the specilic structural features of our vertically reciprocal trolley, the elevating and supporting mechanism therefor, the supporting framework for our lift, and the cooperating fork, pallet and boom structure.

Other and further objects of our invention are those apparent and inherent in the apparatus as described, pictured and claimed.

To the accomplishment of the foregoing and related ends, this invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodirnents of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

This invention will be described with reference to the drawings in which corresponding numerals refer to the same parts and in which:

Figure l is a front elevation of the instant invention;

Figure 2 is a rear elevation thereof;

Figure 3 is a side elevation, partially in section, and showing the lifting mechanism; t

Figure 4 is a view taken along the line and in the direction of the arrows 4 4 of Figure l;

Figure 5 is a fragmentary vertical sectional view showing the locking mechanism of our invention;

Figure 6 is a side elevational view, partially in section and showing the lift boom in position; and

Figure 7 is a fragmentary, vertical sectional view of the pallet and supportingstructure of our invention.

Referring now to the drawings and specifically to Figures 1 and 3, our invention comprises a mobile lift supporting trame generally designated 1b, provided with front and rear wheels 11 and 12 journalled for rotation therein. Wheels 11 are journalled for rotation about a lixed horizontal Aaxis and are each supported at the exterior end of a forwardly extending channel arm 13. Each ice of the channel arms 13 is provided at its interior endl with an integral plate 14 which is bolted or otherwise suitably secured to the depending flange 15 of a base plate 15, 17. Flange 15 of base plate 1S, 17 is a vertical llange and immovably fixed with reference to the horizontal flange 17 by one or more gussets 16.

Wheels 12 are conventional caster wheels and are afxed to horizontal ange 17 by bolts or other suitable securing means. Caster wheels 12 are journalled for rotation about a horizontal asis which is in turn journalled for rotation about a vertical axis in the .conventional manner.

Also, secured to the horizontal tlange 177 of base plate 15, 17 by welding or other suitable means toform a xed integral structure is an upright or standard 18. Standard 18 is of channel-shaped cross-section as shown best in Figure 4 and is provided with opposed edge ilanges 19 and 2li at the open edges of the channel. Standard 18 is braced by a pair of back angle braces 21 or the configuration best shown in Figures l and 2, connecting the standard 18 with horizontal ange 17 and as shown best in Figure l.

Back braces 21 are reinforced by a single horizontal brace 21A connecting them to each other and to the back of standard 1S. Braces 21 are likewise reinforced by cross braces 21B positioned adjacent the lower ends thereof as shown in Figures l and 2.

The Opposed front ianges 19 Vand Ztl of standard 18 serve as a vertical trackway for a vertically movable trolley unit generally designated 22. Trolley 22 as shown best with reference to Figures l and 2 comprises a pair of vertically extending and spaced parallel plates 23 to which are secured upper Vrollers 2 and lower rollers 25. Plates 23 are joined at their forward edges to a lift arm supporting plate 26 which is lixedly connected to plates 23 by any suitable means such as welding. Plates 23 are also joinedV to lift supporting plate 26 by a plurality of horizontal strengthening gussets 2S.

From inspection of the drawings, it will be seen that the upper rollers 24 of trolley 23 are opposed and vertically staggered from lower rollers 25 which bear on the front of the llanges 19 and 2i) whereas upper rollers 24 bear on the rear of the tianges. This serves to prevent tilting of plate 26 when torque is exerted on plate 26 by a load on fork arms 44 as will be subsequently explained. 4 v

One end 29 of a chain Si) is secured to the plate 2,6 for controlling upward and downward movement of the trolley 22. Chain Sil is passed over a sprocket 31 and the other end 32 thereof is iixedly secured to a supporting plate 33 positioned within the channel cross-section of upright 13. I

Supporting plate 33 also serves to support oneend of a hydraulic cylinder 3e in spaced relation to standard 18, the other end of which is iixedly supported on horizontal ilange 17. Cylinder 34 is provided with a piston 35 having a'clevis 35 at its end to which the sprocket 31 1s pivoted.V Thus, it will be seen Vthat the cylinder 34 and piston 35 are mounted within the channel crosssection interior of standard 13 and in spaced relation thereto. Y

hydraulic pump and reservoir, generally designated vEES 1s positionedon the back of the uprightor standard 13 and secured thereto at its upper and lower ends. The pump and reservoir is provided with a handlev 39 and a hydraulic line disconnected to the bottom of the cylinder Se for supplying lluid thereto. Handle 39 is normally retained in the position shown in Figures 3 and 6 by a chain i1 connected to a sleeve 42 thereon. A valve 43 is provided for the pump and reservoir 35 which may be closed to maintain the piston 35 and trolley 2 2 in any elevated position.

moved if desired. Removably positioned upon the arms 44 is ahorizontal lift or pallet plate `46V upon which any load desired to be lifted maybe positioned.

The lift plate or pallet plate 47 is provided with a single hook 47A at one end thereof and centrally located. This hookserves'to engage the rear face of plate 26 (shown in Figure 7 in order to retain the-lift plate 47 in position upon arms 44 as shown best in Figures 3 and 7. yAdditional locatingV lugs or stops may be positioned onplate 47 for cooperation with fork arms 44 if desired.

Positioned at the center of plate 26-is an aperture 50 in which may be inserted the turned end 48A of support rod 48 for boom 49. Rod 48 is pivotally connected to boom 49 at pivot 53. One end of boom 49 is removably pivoted by pin 51 in apertures 52 of standard 18, as shown bestwith reference to Figures 3 and 6.

' The other extending end yof boom 49 is provided with a pivoted clevis 55 which may be utilized to support a chain 56'having an end hook 58 for supporting an object 59 to be elevated.

' Positioned on horizontal flange 17 as shown best in Figure 5, is a surface lock generally designated 60 for immovably positioning the frame with reference to the supporting surface. The lock 60 is secured to the horizontal ange 17 by means of boltsV or'other suitable means.

' It is provided with a toggle link 61 having one end piv- Vof plate 66 is reciprocal in boss 69 secured to plate 62.

A second compression spring 70 positioned within boss 69 serves to bias shank 66 to its upward or retracted positionras shown in Figure 5. Thus, it will be seen that the pedal extension 64 may be engaged by the foot to depress it to the dotted line position of Figure 5 whereupon the links 61 and 63 assume an over-center position and lock the frame with reference to the supporting surface. Likewise, when it is desired to freeY the frame fromA the surface the pedal extension 64 is elevated from the dotted line to the full line position of Figure 5.

In operation, the handle 39 may be reciprocated in the conventional manner to force fluid from the pump and reservoir 3S through conduit 40 and into the cylinder 34 to force the piston 35 upwardly with reference to Figures-3 and 6. This elevates the trolley 22. When it is desired to m'aintain'the trolley 22 in elevated position,

through the line 40'to the pump and reservoir 3S. However, when it is desired to depress the trolley, the valve is opened and gravity acting on the trolley will force the piston 35 backrinto cylinder 34 and thus return uid Ythrough lineY 40. Theftrolleymay Vbe utilized with the fork lift members 44 alone or with the fork lift members 44'having the pallet 47 positioned thereon. fLikethe exterior end of the boom. Since the boom is rela-Y tively removable from the standard 18, kthe boom may be Vremoved or replaced at will.

' valve 43 is closed to prevent the return of hydraulic uid Thus, itwill be seen thatour trolley operates to pro- Y.

vide Va fork hydraulic lift, a platform hydraulic lift or a hydraulically-lifted boom. 7 ,1 `A 1 p As many apparently widely different embodiments of this invention may be obtained without departing from the spirit and scope thereof, it is to be understood that we do not limit ourselves specifically to the embodiments disclosed herein.

What We claim is:

l. ln combination, a supporting frame including a vertical guideway having a pair of opposed anges extending in the same plane, a reciprocal member positioned for vertical travel on said anges, said reciprocal member comprising a vertically extending planar member, wheeled supporting means on said planar member `for engaging said opposed anges, means for reciprocating said reciprocal member, boom means pivoted atV one-end of said vertical guideway and connecting means connecting said boomV means to said reciprocal member for the pivotal elevation thereof. i

2. ln combination, a supporting frame including a vertical guideway having a pair of opposed'flanges extendingin the same plane, a hydraulic cylinder positioned within said guidevvay, a pump means'positioned on said frame and having a connection to said hydraulic cylinder,.said hydraulic cylinder being provided with a piston extending Within said guideway, a chain having one end connected to said guideway and the other end connected to a vertical planar member, a sprocket positioned on the exterior Vend of said piston and engaging said chain intermediate its ends, wheeled supporting means on said planar member for engaging said opposed anges, and a pair of fork arms provided with hangers positioned on and depending from said planar member.

3. The apparatuspof claim 2 further characterized by a pallet supporting plate removably positioned on Vsaid fork arms and having means for maintaining the same in position thereon.

4. The apparatus of claim 2 further characterized by hook meansV on said depending fork arms for engaging the `top and bottom edges of said planar member.

5. A lifting mechanism comprising in combination a Y supporting frame including a vertical .guide means, a reciprocal member positioned for vertical travel on said guide means and havinga horizontal edge, means for reciprocating'said member, a cantilever means removably positioned on said reciprocal member including a pair of spaced supporting arms forrsupportingV a planar load supporting surface adjacent Vsaid horizontal edge, aplauar load supporting surface positioned upon and supported on said cantilever means, an offset extension on saidA planar supporting surface for engaging said horizontal edgefor retaining said planar surface in position upon said arm means.

6. A lifting mechanism comprising in combination a supporting frame including a vertical guide lmeans, a reciprocal member positioned forV vertical travel onV said guide means including a pair of spaced horizontal edges, means for reciprocating said member, a pair of Vcantilever arms removably positioned on Ysaid reciprocal member, and said cantilever arms having oppositely turned hook means for engaging said horizontal edges. l

` References Cited in the le of this patent UNITED STATES PATENTS 668,681 French AFebf26, '1901 1,227,646 Metz May 29,1917 1,789,025 Shepard et al. Jan. v13V, 1931 2,113,879 Delalandre Apr. 12,1938 2,395,345 VSchreck Feb. 19, 1946 2,445,614 Flynn et al. `July 20,1948 2,456,320 Repke Dec; 14, 1948 2,517,813 ,-:Wallace Aug. 8, 1950 Y 2,560,131 Sasgen etal July 10, 1951 2,604,640 Junkin July 29,719.52 2,605,002 Graves July 29,V 1952 2,643,740 Y Quayle June 30, 1953 2,668,602 Cushman Feb. 9, 1954 2,707,573 Balwics May 3, 1955 

